Mitosis

• What are the 2 types of cell division in eukaryotes?

  Mitosis and meiosis
• what divides in mitosis?

  a parent cell
• Why is mitosis needed?

  for the growth of multicellular organisms and for repairing damaged tissues
• in multicellular organisms, do all cells keep their ability to divide?


  NO - the ones that do follow a cell cycle
• What is mitosis part of?

  The cell cycle
• What is G2?

  Gap phase 2
• What is G1?

  Gap phase 1
• What is M?


  Mitosis
• What is S?

  Synthesis
• What does interphase consist of AND IN WHAT ORDER?

  G1, S ,G2
• What are the 3 main phases in the cell cycle?

  Interphase

  Mitosis

  Cytokenesis
• What happens during the G1 PHASE?

  • The cell grows and develops
  • Normal cell processes occur
  • Cell makes proteins needed for cell division
  • ATP is produced for the energy intensive process of cell division about to occur
• What happens during the S PHASE?

  • The genetic material is copied
  • Chromosomes replicate and become double stranded chromatids
• What happens during the G2 PHASE?

  • The organelles duplicate
  • More cytoplasm is produced as the cell grows further ready for division
  • DNA is checked for errors
• What do cyclins do?

  Bind to enzymes called cyclin-dependent kinases

  These then become active
• What do cyclin-dependent kinases do?

  They cause phosphate groups to attach to proteins

  These proteins then become active and carry out tasks specific to one of the phases of the cell cycle

  Unless these reach a THRESHOLD CONCENTRATION, THE NEXT PHASE ISN'T ACTIVATED
• What is mitosis very simply?

  DIVISION OF THE NUCLEUS
• What is cytokinesis very simply?

  division of the cytoplasm
• What increases during interphase?

  cell volume increases
• What is happening to the DNA during interphase?

  Chromosomes are dispersed during interphase and are known as CHROMATIN

  In the NUCLEOLUS, rRNA transcription and ribosomal assembly is taking place- protein synthesis
• what is a chromosome made up of?

  2 sister chromatids and a centromere
• What is an anagram to remember the stages of mitosis?

  PMAT
• What is stage 1 of mitosis?

  prophase
• what is stage 2 of mitosis?

  metaphase
• what is stage 3 of mitosis?

  anaphase
• what is stage 4 of mitosis?

  telophase
• what are the stages of mitosis?

  prophase metaphase anaphase telophase
• What happens during PROPHASE?


  • Nucleolus disappears
  • Chromatin condenses into chromosomes
  • Separation of entrosomes
  • Formation of the miotic spindle
• What happens during METAPHASE?


  • Chromosomes align in the metaphase plate
• What happens during ANAPHASE?

  Chromatids separate towards opposite poles
• What happens during TELOPHASE?

  • New nuclear envelope forms
  • Chromosomes unfold back into chromatin
  • Nucleoli reappear
  • Cell continues to elongate
• Is DNA copied during interphase or prophase?


  INTERPHASE
• What happens after mitosis?

  Cytokinesis takes place (daughter cells divide)
• Is DNA copied during prophase?


  no
• Is DNA copied during interphase?

  yes